Installing a high-efficiency boiler and converting the system to pumped-water is not a cheap thing to do either. Ripping out a steam system and installing a more appropriately sized (for the heat load) cast iron boiler + baseboards is likely to be north of 10 grand, and any conversion going with a modulating condensing boiler is likely to come in twice that.
Going from radiators to cheap fin-tube baseboard is a big step down in comfort- I can see why a house-flipper might go that route in a project house, but not so much on a house you were fixing up to LIVE in for the next decade or two!
Re-using
CAST IRON baseboard or re-using big pumped-water
cast iron radiators can be almost as cheap as fin-tube, even after you've sandblasted & painted them, but you have to size them correctly for the loads of the rooms to get the balance right.
Converting 1-pipe steam can be labor & plumbing intensive, and may or may not have sufficient radiation to deliver the heat at condensing-boiler temperatures (but usually would at 83% efficiency hydronic cast iron boiler temps.)
Before doing any conversion, do a room by room heat load calculation. Almost all cast-iron boilers are going to be 2x oversized for the true heat loads of average sized houses in NJ, but whether a modulating condensing boiler would ever pay off in within it's anticipated lifetime depends on your anticipated fuel costs.
If the oil boiler isn't some ancient asbestos-clad piece o' junk it may make better financial sense to install a conversion burner, or to install a couple of mini-split heat pumps and only use the steam for backup (and enjoy high-efficiency air conditioning too.) With the new or cleaned up radiator vents (thermostatic vents, if you want to micro-zone) even a 1980s vintage steam boiler on a system with insulated pipes can deliver ~75% efficiency or slightly better with a conversion burner. If older than 1980 it probably has high standby loss, especially if it doesn't have a flue damper (either barometric or ignition-cycle automated.) If the boiler room is the warmest place in the house on design day, it's probably worth getting rid of it.